The crash means 21 people have died on the state's roads since December 15, which marked the start of Operation Safe Arrival, the state's Christmas and New Year road safety campaign.

Seven people were killed during the same period last year.

“This Christmas and New Year period is meant to be a time of happiness and to spend time with family and sadly for many, this has resulted in tragedy," he said.

"Out of these 21 deaths, 11 road users have been involved in matters where their vehicles have simply left the road and crashed into a telegraph pole or a tree.

“There are more cars on our roads and sadly, personal responsibility is lacking many road users. The impact of road trauma is significant.

"Out of 433,000 random breath tests, 739 drivers are facing the courts in the New Year for a range of drink-driving charges putting themselves, their passengers and other road users at great risk right throughout the NSW road network."

Also yesterday, a 25-year-old woman was killed in a crash at Taree, on the NSW mid north coast.

She was heading north on the Pacific Highway at Glenthorne just after 5pm when her car left the road and hit a number of trees.

The woman died at the scene.

A 25-year-old woman was killed in a crash at Taree after her car left the road and hit a number of trees. (9NEWS) ()

A male pedestrian in his 70s, who was struck by a car at Bonnyrigg Plaza a few days before Christmas, succumbed to his injuries on Boxing Day, a spokesman for NSW Police confirmed.

Last night, a 42-year-old man died when his car crashed into a parked semi-trailer truck in Emu Plains, in Sydney's west.

A 63-year-old man was killed when his car left the road at Pappinbarra, near Port Macquarie, and he was ejected from the vehicle.

A female passenger, 23, was killed on the Newell Highway at Peak Hill, north of Parkes, when she fell out of a Jeep and hit a road sign.

It has been a tragic 24 hours on the state's roads with seven people not returning to their loved ones these holidays.

Assistant Commissioner Michael Corboy said the deaths left police angry but not disheartened.

"We have gone from disappointed to being angry and that's an understatement," he said.

"It has actually strengthened our resolve and we will be putting in place more and more police officers from now until the end of the year.

"Many of these incidents are totally preventable if people would just slow down, rest and not be distracted during their trip.”

Operation Safe Arrival ends at 11.59pm on January 1, as do double demerits.

With AAP.

A 42-year-old man died when his car crashed into a parked semi-trailer truck in Emu Plains last night. (9NEWS) ()

LIST OF FATALITIES

December 16

A 28-year-old man died after a single-vehicle crash at Mt Druitt

A 53-year-old man died after a single-vehicle crash at Barellan (near Griffith)

A 39-year-old woman died after a single-vehicle crash at St Marys

A 38-year-old woman died after a single-vehicle crash at Yeoval (near Dubbo)

December 17

An 18-year-old man died after a single-vehicle crash at Coolabah (near Nyngan)

December 21

A 24-year-old man and a 15-year-old girl died after a single-vehicle crash at Darlington Point (near Griffith)

A 21-year-old woman died when hit by a car at Wallsend

December 22

A 77-year-old woman died after being hit by a car at St Leonards

A 72-year-old man died after a multi-vehicle crash at Carlingford

A 48-year-old man died after a multi-vehicle crash at Fernside (near Kyogle)

December 23

A 27-year-old man died when his motorcycle crashed at Dorrigo

A 25-year-old man died when a car and taxi collided in Walcha

December 25

A 44-year-old man died after a single-vehicle crash at Beelbangera (near Griffith)

December 26

A 63-year-old man died after a single-vehicle crash at Pappinbarra (near Port Macquarie)

Three people died in a head-on crash south of Sussex Inlet (they are yet to be identified).

A 25-year-old woman died after a single-vehicle crash at Glenthorne (near Taree)

A 23-year-old woman died after falling from a 4WD at Peak Hill (near Parkes)

A 43-year-old man died after a single-vehicle crash at Emu Plains

(NB: The deaths of a two-year-old girl (Campsie) and a 53-year-old man (Bonnyrigg) have not been included in these statistics as inquiries have revealed they occurred on private property.)